Selective signaling system and apparatus therefor.



J. A. HULTT.

SELECTIVE SIGNALING SYSTEM AND APPARATUS THEREFOR.

APPLICATION FILED OCT. 21. 1911.

Patented Apr. 25,1916.

4 SHEETS$HEET l.

d I I. Q /TO//XEEY SELECTIVE SIGNALING J. A. H ULIT. SYSTEM ANDAPPARATUS THEREFOR.

APPLICATION FILED OCT. 21. 9H.

Patented Apr. 25,1916. I

4 SHEETS-SHEET 2- MZMALML- Y J. A. HUNT- SELECTIVE SIGNALING SYSTEM ANDAPPARATUS THEREFOR.

APPLICATION FILED OCT. 21. 1911.

a w W7 A m.% 1 ma@ m m m A M a fl m a w WW w W W W. ,1, m F .F fl 4 A[MT/ E5555 Q J. A. HULIT. SELECTIVE SIGNALING SYSTEM AND APPARQTUSTHEREFOR APPLICATION FILED OCT. 21,191!- 1,180,293. Patented Apr.25,1916.

4 SHEETS-SHEET 4.

II I

Ill

MENTOR:

w MMC JOHN A. H'ULIT, or on caeo, rumors, ASSIGNOR 'ro AUTOMATICnnnornrc COMPAMY,

OF CHICAGO, ILLINOIS, A CORPOMTION OF ILLINOIS.

SELECTIVE SIGNALING- SYSTEM AND APPARATUS THEREFOR.

Specification of Letters Patent.

Patented Apr- 25, 1916.

nnlicati'on filed October 21, 1911. Serial No. 655,946.

. tion, it is designed principally for use in connection with telephonetrain despatching systems.

Among the objects of my invention are to provide an improvedconstruction for the station selector, signal transmitter andanswer-back apparatus for use in such a signaling system. The stationselector is an improvement over my prior patents N'o.

795,836, granted -August 1, 1905, and No. 896,832, granted August 25,1908. It contains various improvements over these pat? ents, whichimprovements tend to simplify and improve the operation of theapparatus.-v When apparatus of'this type-is employed in train desetching telephone systems, it. is often desirable to employ" the sameline for telegraphic purposes. therefore becomesnecessary to deviseaisslective apparatus which is not responsive to these telegraphicimpulses, but is responsive to-a code series of impulses. r An 'objectof my invention is to provid'e such a station selector which is notoperated by telegraphic impulses, nor by a succession of regularimpulses, but is operated by an irregular succession of rapid impulses.

A'further object of my invention is to improve the construction of thecall-sending mechanism for transmitting the impulses for controlling thestation selector. A further object is to provide an improved answer-backdevice whereby the operator is advisedof the fact that the properstation is being signaled.

These-and other objects of my invention. will be more clearly understoodby reference to the accompanying drawings, in which- Figures 1 and 2 area plan view and ole-- 'vation, respectively, of the station selector.

Fig. 3 is a detail view of the code or combination wheel of theselector. Fig. 4 is a? plan view of the combination call-sending devicewith the cover plate removed. Fig. 5 is a side elevation of the same. anend elevation of the same. Fig. is a view of'a section taken on the line77 in Fig. 5. 1 Fig. 8 is a view ofa portionof the side plate which isremoved from Fi-g. 5. Fig. 9 is an elevation of the substationanswer-back device. Fig. 10 is aplan view of the same. Fig. 11 is a topview of the same with the top plate removed. Fig.'12 representsdiagrammatically a'telephon'e line in whlch are connectedtwo substationsA. and A, each substation beiii'gequipped with a telephone, a stationselector, a call-sending device and an answer-back device. Al-

though only two substations. are shown, any

number of similarly equipped substations may be connected in the lineina similar manner to the two substations shown. I

. Referring first to the substation selector shown in Figs. 1, 2 and'3,theupright frame plates 2 and 3, which may be rigidly se cured to anydesired base, form a frame between which the greater partof the mochanism is mounted. .Journaledin' the plates I 2 and 3 there is a shaft 4carrying rig-idly secured thereto a ratchet wheel 5 and a coma bination'or code wheel, 61 Thesmall spiral spring 7 normally tends torotatethe shaft I i in a counter-clockwise direction, as shown in Fig. 2. Theshaft 4 is held in normalposition against the tension-of the spring 7 bythe engagement of the lug 8 onthewheel 5 with the stationary screw 9.Loosely mounted on the shaft 4 there is a sleeve 10 wheel '11. The flatspiral spring 12 normally' tends to turn the sleeve 10 and ratchetwheelll in a counter-clockwise di motion, as shown in Fig. -2. The wheel11' is retained in normal position again'st'the of the lug 13 with thestop screw 1%. se-

neath the frame 23 there is an electromag-- .net 15 provided with amovable armature to which there is secured, a second ratchet tension ofthe spring 12 by the engagement j them in their advanced positions.\Vhen the magnet 15 is deenergized, the propelling pawl is pulledforward by the helical spring 20 to rotate the ratchet wheels. Thespring 21 serves to hold the pawl down into the teeth of the ratchetwheels. The pin 22 serves to prevent the pawl 18 from rising out of theteeth of the ratchet when it is pulled forward, and the pin serves as astop to prevent the propelling pawl from falling more than enough toengage the next notch of the ratchet wheels when the magnet 15 isenergized. Thus each time the magnet is energized and dee'nergized. thewheels 5 and 11 are rotated one tooth.

A throw-off is provided for the holding pawl 19 and comprises a balancewheel 24 mounted upon a shaft which is pivoted in the ends of the screws25 and 26. This bal ance wheel is weighted so that when freed it turnsslowly in a clockwise direction. When the wheel has completed a certainportion of a revolution from the position shown in Fig. .2, the pin 27strikes the tailpiece of the holding pawl 19, forcing said .pawl out ofengagement with the teeth of the ratchet wheels and allowing them to beretracted. The balance wheel 2+l is held in the position shown in Fig. 2by the spring acting through the medium of the arm .29, the rotatableshaft 30 and the arm 31, which arm 31 engages the pin 32 in the wheel.The pin 33 in the plate 3 serves as a normal stop for the balance wheel.Attached to the upper end of the armature 16 there is a hook 3 l which,when the magnet 16 is energized, engages the arm 29 so as to rotate theshaft 30 slightly to raise the arm 31 from the pin 32 to free thebalance wheel 24:. Attached to the inside of the plate 2 there is ablock of insulation upon which there is mounted a contact spring 36,

the end of which spring is adapted to be en- 7 gage'd by a pin 37 in thewheel 6 after said wheel has been rotated through a certainpredetermined distance. 'Around the periphery of the wheel 6 there are anumber of notches the spaces between which correspond to the spacesbetween a certain number of teeth of the ratchet wheel 5. These notchesin thewheel 6 are adapted to be engaged by a pin 38 in a balance lever39 (Fig. 3), whereby said wheel and the shaft 4 maybe held in certainadvanced positions independently of the holding pawl 19. The lever 39 isnearly balanced, so that the pin 38 moves into the notches slowly, sothat as the wheel 6 is returning to normal position the notches pass thepin 38 so rapidly as not to permit it to drop into them and arrest themotion.

. .The holding pawl 19 has only a slight preponderance of weight on theside which tends to turn it in a clockwise direction to hold it in theteeth of the wheels 5 and 11.

to the same shaft as the holding pawl 19,

by its engagement with the shaft 4:, limits the backward movement of theholding pawl to prevent it from being thrown back too far. i

The method of operation of the selector is as follows: In order tosignal any station. the wheel 6 at that station must be rotated to bringthe pin 37 into contact with the spring 36 so as to close the signalcircuit. It will be seen that the teeth on the ratchet wheel 11 do notextend entirely around the periphery. certain distance (eight steps fromnormal in the particular instance shown), the smooth surface of thewheel 11 will engage the hold ing pawl 19 and force it out of engagementwith the ratchet wheel 5, so that when the propelling pawl is withdrawn,said wheel 5 and the wheel 6 will be restored to normal position. Thenumber of steps through which the wheels may be rotated before they arereleased in the above manner by the wheel 11 is notsuificient to carrythe pin 37 into engagement with the spring 36. It will thus be seen thatthe station cannot be sig naled by simply sending in enough impulses tostep the wheels around the desired distance. In order to completethe'signal circuit the wheel (5 must be rotated a portion of the desiredamount and then be held in this position while the pawl 19 is withdrawnto. permit the wheel 11 to be released and returned to normal position.It is the purpose of the notches in the wheel 6 and the lever 39 to holdthe wheel 6 in its advanced position when the pawl 19 is withdrawn topermit the wheel 11 to be. retracted.

In detail the manner of completing the operation is as follows: Themagnet 15 is first energized towithdraw the pawl 18 and is heldenergized long enough to permit the throw-off 24 to rotate far enough tothrow off the pawl 19, whereupon the wheels 11, 5 and 6 return to normalposition, they being held one step advanced therefrom when the magnet 15is deenergi'zed. Themagnet is then denergized and energized momenta rilya. suflicient number of times to advance the wheels 5 and 11 step bystep until a notch in the wheel 6 comes opposite the pin 38 on the lever39. The energizations of the magnet between these steps must be onlymomentary, so as not to permit the throwold to throw ofl the holdingpawl 19, and the Thus, if said wheel is rotated a deenergizations mustbe long enough to per- 'mit the holding pawl to drop in each time beforethe magnet is energized. After the last step which permits the pin 38 todrop into a notch, the magnet 15 is energized for a longer period,whereupon the throw-oil withdrawsthe holding pawl 19. This per-- mitsthe ratchet wheel 11 to be retracted, but

' the wheels 5' and 6 remain in their advanced positions by reason'ofthe engagement of the pin 38 with a notch in the wheel 6. After thewheel 11 has had time to be released, the above operations are, repeatedto rotate the wheels until the pin 38 drops into the next notch in thewheel 6, when the wheel 11 is again released. These operations arerepeated until the pin 37 finally engages the spring 36. Assuming thatthe notches of the wheel 6 are spaced as shown in F ig '3, and that thepin 38 in the normal posltion of the Wheel engages the lowest or firstnotch,

i it will be seen that two steps are required to bring the wheel to thenext stop position, four 'more steps will bring it'to the next stop,position, five to the next, and then five more steps will bring the pin37 against the spring 36. Thus the numberof the instrument containingthe wheel shown in Fig. 6 may be said to be 2455. It is to be understood-that the combination wheels 6 of all the different selectors 'on aline are arranged for a different combination of, impulses-.-

.that is, the notches are spaeeddifi'erently.

Thus, although the operating magnets of all the selectors may beoperated in unison by any combination of impulses, only the selec-- torhaving a combination wheel corresponding toy that particular combinationof impulses will be operated to close its-signal circuit. Thecombination wheels of all other selectors will be automatically released,one or more times during the operation. Although the notches of thecombination wheels of all the selectors are-spaced d1fferently, thetotal number of steps reqnired to close the signal circuit is preferablythe same in all the selectors. There is ne notch in the wheel 6 to beengaged by the pin 38 when said wheel is in its most advanced position,so that said wheel isrelease'd the first time the magnet 15 is energizedafter the call has been made. i

Referring now to Figs. 4*, 5," 6," 7 and 8.

the construction 'of the cal-Lsendmg apparatus is as follows: The entiremechanism is contained in a metal case. Journaled between the end wall40 and the partition 41 there is-ashaft 42 to Whicharefirmly secured aplurality of toothed wheels 43. Above these wheels there is a swingingframe comprising the pivoted shaft .44, the side arms 45 and 46 securelyfastened to said shaft, andthe-cross 47. Loosely mounted upon a shaft 48thereisa-pawl 49 the end of which isfadaptedto be engegedfby the rod.55'which slides upon a shaft 56.

42 to. rotate'the impulse wheels 43.

before the wheels have completed teeth of one of thewheels 43 duringtheir rotation. The cross bar 47 of the swinging frame described aboverests u on the top of the end of the pawl 49, and the end of the:

spring 50- of the pair of contact springs 50 and 51 rests upon the topof the arm 46. When the pawl 49 is raised by the teeth of the wheel 43it swings the frame upward, thereby separating the springs 50 and 51.Slidably mounted upon a shaft 52 there is 'a member 53 provided with afork which fits over the rear end of the pawl 49. To the member 53 thereis attached a handle or lever 54 .which extends out through aslot' inthe wall ofthe case.- By means of this handlethe pawl 49 maybe movedlaterally to engage any oneof the wheels'48 desired-. An indicator onthe outside of the case (Fig. 8) shows'which wheel the pawl 1s 1nPOSItiOIl'tO engage. To prevent the pawl? 48 from falling down betweenthe wheels, isprovided with a projecting pen the end of the shaft 42which --pro]'ects through the partition 41 thereis attached a. geanwheel57 which meshes with a gear-- wheel 58 which is loosely. mounted upon ashaft 59. Securely attached .to the shaft 59 there is a lever 60 and aratchet wheel 61, which latter is adapted to be engaged by a pawl 65 onthe side of the gear wheel 58.

On the opp0site side of the gear wh'eel. there of the one with which itwas previously resting in engagement. When the lever 60 is released itis returned to its upper-position by the-spring 62, and the ratchetwheel 61 engaging the pawl 65 forces the gear wheel 58 to rotate withit. The rotation of the gear Wheel 58 is transmitted to the shaft ()necomplete stroke of the lever 60 is su'fiicient to rotate the shaft 42and wheels 43 through a complete revolution. In order to positively stopthe shaft 42 after it has completed its revolution, there is secured tosaid shaft a stop lever 66 which is adapted to engage the stop 67 on theshaft 59 when the lever '60 is at the top of its" stroke.

lVhen the lever'60 is pulled down, the stop 67 passes out of the path ofthe lever 66, thereby releasing the impulsewhe'els; but

tion, the stop 67 is returned to its normal position to be engaged bythe lever 66. The speed of rotation of the impulse wheels is governed bythe escapement 68 operating through the medium of the gearwheel 69. In

a revolu orderto provide means for properly lini 11g up the impulsewheels, a hole 15 placed through 'each wheel in exact relation withregard to the normal or. starting point, and a pin 74 is then runthrough all the wheels. This insures that the normal or starting pointof all the wheels will hein a straight line when magnet of the selectoris controlled through the back contact of a relay. The relay iscontrolled by the springs 50 and 51 of the call-sending apparatus.Therefore, the operating magnet deenergizes to step the ratchet wheelsaround each time the pawl 49 of the call-sending device drops into anotch to permit the springs 50 and 51 to close. The codes will then herepresented on the wheels of the call sending device by a number ofseries of short teeth representing momentary energizations of theoperating magnet of the selector, followed by a longer toothrepresenting a longer energization of the magnets. The long teeth oncachwheel will correspond to the notches in the combination wheel of theparticular selector represented by that impulse wheel in thecall-sending device. Before beginning the code proper, there are twolong teeth on each of the impulse wheels which are for the purpose ofinsuring. that all the selectors will he returnedto normal positionbefore the impulses of the code are being sent in. These two impulseswill cause two successive long energizations of the operating magnets ofthe selectors, which will insure that, all of the combination wheelswill he returned to normal position whether they resting with the pin 38in a notch or not. The spaces between the teeth of the impulse wheelsare comparatively long. This is to insure that the magnets of theselectors shall remain dei nergized long enough each time toallowtlie'holding pawl 19 to drop into the teeth of the ratchet wheelsbefore the magnet is again energized. Thus. while the impulses sent outby the calI-scmling device are of theproper character to progress theratchet wheels. the short dots and dashes representing Morse characters,as produced by an ordinary telegraph key. will he too short to permitthe holding pawls of the selectors to drop into the ratchet teeth whilethe oy'icrating magnets are dei nen gized, and said Morse characterswill, therefore, not progress the ratchet wheels. Thus. since theordinary dots and dashes repre senting ll'ltilsl" characters areincapahle of progressing the ratchet wheels of the station selectors, aline equipped with said selectors may he used as an ordinary telegraphline without falsely operating the selectors.

The answer-back device shown in Figs. 9, l0 and 11 comprises a frameconsisting of two plates 76 and 7 7 secured to the posts 78, 7 9 and 80.Journaled in the plates 76 and 7 7 there is a shaft 81 to the upper endof which there is secured a pointer or indicator 75. Between the plates76 and 77 there is firmly secured to the shaft 81 a ratchet wheel 82,and just beneath this ratchet, and loosely mounted ,on the shaft, thereis a gear wheel 83. Beneath the gear wheel there is a coiled spring 8%,the inner end of which spring is attached to the shaft 81, while theouter end of the spring is secured to the post 79. Upon the top of thegear wheel 83 there is a pawl 103 which engages the ratchet wheel 82.The gear wheel 83 meshes with a pinion 85 on a shaft upon the upper endof which there is a toothed wheel 8., the teeth of which wheel arearranged to correspond to the dots and dashes representing v a Morsecharacter. The teeth on the Wheel 87 at each station are to be arrangedto give a different character. The teeth or raised portions of the wheel87 are adapted to contact with the insulated spring 88 during therotation of said wheel. The gear wheel 89 is also secured to the shaft86 and meshes with a gear 90 which is secured to the escapement wheel 91through the medium of which the speed of operation of the device iscontrolled. The apparatus is normally locked in the position shown inFigs. 10 and 11 by the engagement of a pin 92 in the wheel 89 with a pin93 in the side of the lever 9+; In the end of the leve1-9-l there is apin 95 which extends downward into a slot in a lever 96, the end ofwhich lever 96 strikes upon the end of the armature 97 of theelectromagnet 98 and thereby preventsthe pin 93 from being movedout ofthe path of the pin 92. \Vhen the magnet 98 is energized, the armature97 disengages the lever 96, which permits the pin 93 to free the pin 92.The shafts 81 and 86 then hegin to rotate. When the shaft 81 has made aportion of a revolution to bring the stop 98 down into the path of thepin 99, as shown in dotted lines in Fig. 10, the wheel 87 has made acomplete revolution, and theengagement of the pin 99 with the stop 98brings the mechanism to rest. In this position of the shaft 81 the pin100 makes-contact with the insulated spring 101. Just before the shaft86 completes its revolution. the pin 92 in the wheel 89 strikes therod102 and turns the lever ill so that the pin 93 again comes into the pathof the pin 92 to lock the mechanism. when the indicator 7:") is manuallyreturned to its original position.

The returning of the indicator to its original position restores thetension to the spring 84 and turns the ratchet wheel 82 so that the pawl103 engages the next notch,

ally exerting a force against the armature 97 and will therefore slipoff and release the mechanism the instant the magnet 98 is energized. Itwill. thus be seen that only a very short impulse through the magnet isrequired to release the mechanism and cause it to make a complete cycle.

- In Fig. 12 each of the substations A and 'A are shown provided with astation selector, a call-sending device and an answerback device of thecharacter described in the preceding paragraphs. In this figure,110wever, the apparatus is represented only diagrammatically, thevarious parts of both substations being represented by the samereference numerals as inv Figs. 1 to 11, in-

'clusiye. The line connecting the substations comprises a single lineconductor, the ground -'being used as a return. Beyond the substa- 1tion A." the line is grounded through an -impedance coil 104, and beforereaohing'the' "substation A the line passes from ground through abattery B and impedance coil 105.

1 back device, wheel 87 and frame of the device, and thence through arelay 106.to the next substation. One terminal of the magnet 98of'theanswer-back device is connected through a battery B with the frameof the station selector, and'therefore with the pin 37. The. otherterminalof the magnet 98 is connected with the spring 36. The frame ofthe answer-back device or the pin 100 is connected through a hell orother suitable signal 107 with one terminal of a battery B the otherterminal-of which battery is connected with the spring 101. Theoperating magnet 15 of the selector is included in the connectionbetween the back contact of the armature of the relay 106 and thebattery 13 Each station is shown provided with an auxiliary telegraphkey 108'and short-circuiting switch 1095 At each substation a telephoneT is bridged between the line and ground.

" Thetelephone may be provided with any suitable hook switch or key foropening and closing its circuits as desired- An ordinary telegraphsounder '110 is also provided, which sounder is connected with the frontcontact of the relay 106.

The complete operation by which one station signals another is asfollows: The operatorat thecalling substation sets the indicatol' of hiscall-sending device to the number of the ,desiredsubstation and thenpul'r. rloyentthe lever=60. As the lever returlff l'tfl) ilormalpositiom the particular ima; pole wheel 43 of the call sender pver whichthe pawl 19 has been placed first separates the springs 50 and 51 twicefor a comparatively long time, each time breaking the cir cuits of allthe relays 106 on the line. Each time these relays denergize they closethe circuits of the magnets 15 at their respective substations. Thesetwo preliminary impulses, as has been explained are for the purpose ofinsuring that thecombination wheels 6 at all the substations shall bereturned to normal. The calling device impulse wheel then proceeds tosend out the particular combination of long and short impulses,corresponding to the station desired. As previously explained, thecombination wheel 6 at this station will be rotated to bring the pin 37into contact with the spring 36, whereby the circuit of the magnet 98 ofthe answer-back device is closed. The magnet 98, upon energizing,releases the mechanism, as previously explained, and allows the wheel 87to make a complete revolution and the pin 100 to come into contact withthe spring 101. The engagement of the pin 100 with the spring 101 closesthe circuit of the bell 107 to signal the attendant; The wheel 87,during its revolution, first opens the line, then closes it a number oftimes, in accordance with the Morse character of the station called, andreturns the line to normal closed condition. The first opening of. thelineallows the re lays 106 to fall back and close the circuits of themagnets 15. At the called substation this energization of the magnet 15releases the combination wheel of the selector. The closing of the linein accordance with the Morse character of the called substation causesthis character to be sounded on the sounders 110 at all the stations.The operator at the calling station, upon hearing this character, knowsthat the proper substation has been called and that the bell at'saidstation is ringing. The attendant at the 'it will beevident thatiffthesystem is one in which the various substations on the line are notsupposed to call each other, but in which the substations are only to-becalled by a master station, only the master station need have acall-sending device. Also, instead ,of -a. single line conductor and aground return, two line conductors may be used if desired and thecontrolling relays 106 may bebridged across the line instead of beingconnected in series, as shown herein. Likewise, while I have shown but apair of substations, it is evident that any number 1. In a signalingsystem, a station selector,.

means for operating said selector by an interrupted series of regularimpulses of greater duration than telegraphic impulses when saidimpulses and interruptions are in a predetermined order, and forpreventing said selector from being operated by a successlon oftelegraphic impulses, and means for preventing said selector from beingoperated by an uninterrupted series of said regular impulses.

2. In a signaling system, a line circuit, means for transmittingtelegraphic impulses over said line circuit, station selectors connectedwith said line, means for transmitting an interrupted series of impulsesof greater duration than said telegraphic impulses over said circuit,means controlled by said impulses for selectively operating saidselectors when said impulses and interruptions are in a predeterminedorder, and for preventing said selectors from being op crated by saidtelegraphic impulses. and means for preventing said selectors from beingoperated by an uninterrupted series. oi regular impulses of greaterduation than telegraphic impulses.

3. in a signaling system. a line circuit. means for transmittingtelegraphic impulses over said circuit. station selectors connected withsaid line. means for transmitting a plurality ol' series of regularimpulses of greater duration than telegraphic impulses over saidcircuit, each ol' said series being separated by one or more prolongedimpulses for selectively operating said station selectors. means Forpreventing said station selectors from being operated by saidtelegraphic impulses. and means for preventing said selectors from beingoperated by an uninterrupted series of regular impulses.

-l. in a signaling system. a station selector including anclectromagnet. a ratchet wheel. a propelling pawl For said ratchet wheelcontrolled by said electronuignct. a holding pawl. a ratchet wheelsegment loosely mounted upon the same shaft with said ratchet wheel.means controlled by said segment for releasing said holding pawl fromthe ratchet wheel to permit the. same to re turn to normal positionafter a certain numher of propelling strokes of said propelling pawl. athird wheel rigidly mounted on the shaft with said ratchet wheel andprovided with a series of notches on its periphery. aml a holding pawltherefor for holding said ratchet wheel in advanced position when saidpawlis in engagement with one of said notch s.

5. In a signaling system, a station selector including a ratchet wheel,a propelling pawl for operating said wheel in a step-by-step manner inone direction, a spring for returning said wheel to normal position, aholding erated by a series of rapid operations of said propelling pawl,said holdingpawl is thrown out of engagement with said ratchet teeth tothereby prevent said ratchet from being operatively rotated.

6. In a signaling system, a station selector including a shaft, aspring-returned ratchet wheel rigidly mounted thereon, a secondspring-returned wheel loosely mounted on said shaft, :1 propelling pawlengaging said wheels, means for'holding said wheels in advancedposition, and means controlled by said second wheel when it has beenadvanced a predetermined distance for rendering said holding meansinoperative.

' 7. In a signaling system, a station selector including a shaft, aspring-returned ratchet wheel rigidly mounted. thereon, a secondspring-returned wheel loosely mounted on said shaft, a propelling paw]engaging said wheels. a holding pawl for holding said wheels in advancedposition. independent means for holding said ratchet wheel in certainselected advanced positions, aml a throw-oft for disengaging saidholding pawl from said wheels to permit said second wheel to return tonormal.

S. In a signaling system, a station selector including a shaft. :1spring-returned ratchet wheel rigidly mounted thereon, a secondspringreturned wheel loosely mounted on said shaft. a propelling pawlengaging said wheels. a holding pawl for holding said wheels in advancedposition, a third wheel rigidly mounted on said shaft and provided witha series of selectively arranged notches. a holding pawl for engagingsaid notches for holding said third \vheeland ratchet wheel in certainadvanced positions. and a throw-oil for disengaging saidfirst-nientioncd holding pawl from said first two wheels to permit saidsecond wheel to return to normal.

5). In a signaling system. a station selector including a shaft. aspring-returned thereon,

ratchet wheel rigidly mounted a second spring-rcturucd wheel looselymounted on said shaft. a propelling pawl engaging said wheels. a holdingpawl for holding said wheels in advanced position,

independent means for holding said ratchet wheel in certain selectedadvanced positions,

and a throw-oil for disengaging said holding pawl from said wheels topermit said second wheel to return to normal, said throw-off being slowacting, whereby it is only brought usages into operation during a pausebetween the series of operations of said propelling pawlv y 10. In asignaling system, a station selector including a shaft, aspring-returned ratchet wheel rigidly mounted thereon, a seconds'pringreturned wheel loosely mounted on said shaft,--a propelling pawlengaging said wheels, an electromagnet'for controlling said propellingpawl, means for transmitting a varying number of impulses through saidmagnet to selectively operate 'saidratchct wheel, means for holding saidwheels in advanced position, and means controlled by said second wheelwhen it has been advanced a predetermined distance for rendering saidholding means inoperative.

1].. In a signaling system, a station se lector including a shaft, aspring-returned ratchet wheel rigidly mounted thereon,

a second spring-returned wheel, looselymounted on said shaft, apropelling pawl engaging said wheels, an electromagnet for controllingsaid propelling pawl, means for transmitting a Varying number ofimpulses through said magnet to selectively operate said ratchet wheel,a holding pawl for holding said wheels in advanced position, independentmeans for' holding said ratchet wheel in certain selected advancedpositions, and a'tl'irow-ofi for disengaging said holding pawl from saidwheels to permit said second wheel to return to'normal.

12. Ina signaling system, astation lector'including a shaft, aspringmeturned ratchetwheel rigidly mounted thereon,

a second spring-returned wheel loosely mounted on said shaft, apropellingpawl engaging said wheels, an electromagnet for controllingsaidpropelling pawl, means for transmitting a varying number of impulsesthrough said .magnet to selectively operate said ratchet wheel, aholding pawl for holding said'wheels in advanced position, a third wheelrigidly mounted on said shaft and provided with a series of selectivelyan first two wheelsto 66 means for holding sai ranged notches, a holdingpawl for engag ing said notches for holding "said third wheel andratchet wheel in certain advanced positions, and a throw-oil" fordisengaging said first-mentioned holding pawl from said permit saidsecond wheel to return to normal.

:13. In a signaling system, a station selector including a shaft, aspring-returned ratchet wheel rigidly mounted thereon, a secondspring-returned wheel loosely mounted on said shaft, :1 propelling pawlengaging said wheels, an electromagnet for controlling said propellingpawl, means for transmitting a varying number of impulses through saidmagnet to selectively operate said' ratchet wheel, a holding pawl forholding said wheels in advanced position, inde endent ratchet whee incertain selected advanced positions, and a throw-oft for disengagingsaid holding pawl I from said wheels to permit said second wheel toreturn to normal, said throw-oi? being ratchet wheel rigidly mountedthereon, a

second spring-returned wheelloosely mounted on said shaft, a propellingpawl engaging said wheels, an. v,electromagnet for controlling saidpropelling paw'l, means for transmitting a varying number of impulsesthrough said magnet to selectively operate said ratchetwheel, a holdingpawl for holding said wheels in advanced position, a third wheel rigidlymounted on said shaft and provided with a series of selectively arrangednotches, a holding pawl for engaging said notches for holding said thirdwheel and ratchet wheel in certain advanced positions, and athrow-oiffor disengaging said first-mentioned holding pawl from said first twowheels to permit said second wheel to return to normal.

15. In a signaling system, .a station selector including aspring-returned ratchet wheel, propelling and holding means therefor, aslow acting throw-oil for the holding means, means-including .a ratchetwheel segment for controlling the forward movement of the ratchet wheel,and selective means associated with the-ratchet wheel for holdr lectorincluding a spring-returned ratchet wheel with propelling and holdingmeans therefor,

means-including a ratchet wheel segment for disengaging said holdingmeans to permit the ratchet wheel to return to normal after a successionof propelling strokes,

and means independent of said segment for holding the, ratchet wheel,whereby the ratchet wheel segment maybe returned to normal withoutreturning the ratchet wheel 17. In' a'signaling system, a stationselector including a spr1ng-returned ratchet wheel, propelling andholding means there for, means including a ratchet wheel segment fordisengaging said holding means to "permit the ratchet wheel to returnto'normal. and means forrestoring both the ratchet wheel and segmentsimultaneously.

18. In a signaling system, a station se-' lector including aspring-returned ratchet wheel, propelling, holding and releasing meanstherefor. and means whereby only a succession of uninterruptedratchet-progressing strokes will means ineffective.

-19. In a signaling system, a station se- 'lector including aspring-returned ratchet wheel, propellingand holding means thererenderthe holding til 1,180,293

for, mechanical. releasing means for the hold-' ing means. whereby a;long pause between propelling strokes will restore the ratchet Wheel.and an independent means for positively holding the ratchet Wheelprogressed.

'20. In a signaling systen'n a station selector including aspring-returned ratchet heel. propelling, holding and releasing meanstherefor, and means whereby a suc- 11') cession of uninterrupted ratchetprogress ing strokes will render the holding means inefieetive saidratchet Wheel moving in a continuous direction in response to saidsuccession of strokes.

Signed by me at Chicago, Cook county, lllinois. this 18th day ofOctober. 1911.

JOHN A. I-IULIT. \Vitnesses:

ARTHUR J. RAY, llmmun l). FALus.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Eatentm,

Washington. D. G.

